diff options
Diffstat (limited to 'crypto/xcbc.c')
| -rw-r--r-- | crypto/xcbc.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/crypto/xcbc.c b/crypto/xcbc.c new file mode 100644 index 000000000..6074c5c1d --- /dev/null +++ b/crypto/xcbc.c @@ -0,0 +1,276 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C)2006 USAGI/WIDE Project + * + * Author: + * Kazunori Miyazawa <miyazawa@linux-ipv6.org> + */ + +#include <crypto/internal/cipher.h> +#include <crypto/internal/hash.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/module.h> + +static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101, + 0x02020202, 0x02020202, 0x02020202, 0x02020202, + 0x03030303, 0x03030303, 0x03030303, 0x03030303}; + +/* + * +------------------------ + * | <parent tfm> + * +------------------------ + * | xcbc_tfm_ctx + * +------------------------ + * | consts (block size * 2) + * +------------------------ + */ +struct xcbc_tfm_ctx { + struct crypto_cipher *child; + u8 ctx[]; +}; + +/* + * +------------------------ + * | <shash desc> + * +------------------------ + * | xcbc_desc_ctx + * +------------------------ + * | odds (block size) + * +------------------------ + * | prev (block size) + * +------------------------ + */ +struct xcbc_desc_ctx { + unsigned int len; + u8 ctx[]; +}; + +#define XCBC_BLOCKSIZE 16 + +static int crypto_xcbc_digest_setkey(struct crypto_shash *parent, + const u8 *inkey, unsigned int keylen) +{ + unsigned long alignmask = crypto_shash_alignmask(parent); + struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent); + u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); + int err = 0; + u8 key1[XCBC_BLOCKSIZE]; + int bs = sizeof(key1); + + if ((err = crypto_cipher_setkey(ctx->child, inkey, keylen))) + return err; + + crypto_cipher_encrypt_one(ctx->child, consts, (u8 *)ks + bs); + crypto_cipher_encrypt_one(ctx->child, consts + bs, (u8 *)ks + bs * 2); + crypto_cipher_encrypt_one(ctx->child, key1, (u8 *)ks); + + return crypto_cipher_setkey(ctx->child, key1, bs); + +} + +static int crypto_xcbc_digest_init(struct shash_desc *pdesc) +{ + unsigned long alignmask = crypto_shash_alignmask(pdesc->tfm); + struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc); + int bs = crypto_shash_blocksize(pdesc->tfm); + u8 *prev = PTR_ALIGN(&ctx->ctx[0], alignmask + 1) + bs; + + ctx->len = 0; + memset(prev, 0, bs); + + return 0; +} + +static int crypto_xcbc_digest_update(struct shash_desc *pdesc, const u8 *p, + unsigned int len) +{ + struct crypto_shash *parent = pdesc->tfm; + unsigned long alignmask = crypto_shash_alignmask(parent); + struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent); + struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc); + struct crypto_cipher *tfm = tctx->child; + int bs = crypto_shash_blocksize(parent); + u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); + u8 *prev = odds + bs; + + /* checking the data can fill the block */ + if ((ctx->len + len) <= bs) { + memcpy(odds + ctx->len, p, len); + ctx->len += len; + return 0; + } + + /* filling odds with new data and encrypting it */ + memcpy(odds + ctx->len, p, bs - ctx->len); + len -= bs - ctx->len; + p += bs - ctx->len; + + crypto_xor(prev, odds, bs); + crypto_cipher_encrypt_one(tfm, prev, prev); + + /* clearing the length */ + ctx->len = 0; + + /* encrypting the rest of data */ + while (len > bs) { + crypto_xor(prev, p, bs); + crypto_cipher_encrypt_one(tfm, prev, prev); + p += bs; + len -= bs; + } + + /* keeping the surplus of blocksize */ + if (len) { + memcpy(odds, p, len); + ctx->len = len; + } + + return 0; +} + +static int crypto_xcbc_digest_final(struct shash_desc *pdesc, u8 *out) +{ + struct crypto_shash *parent = pdesc->tfm; + unsigned long alignmask = crypto_shash_alignmask(parent); + struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent); + struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc); + struct crypto_cipher *tfm = tctx->child; + int bs = crypto_shash_blocksize(parent); + u8 *consts = PTR_ALIGN(&tctx->ctx[0], alignmask + 1); + u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); + u8 *prev = odds + bs; + unsigned int offset = 0; + + if (ctx->len != bs) { + unsigned int rlen; + u8 *p = odds + ctx->len; + + *p = 0x80; + p++; + + rlen = bs - ctx->len -1; + if (rlen) + memset(p, 0, rlen); + + offset += bs; + } + + crypto_xor(prev, odds, bs); + crypto_xor(prev, consts + offset, bs); + + crypto_cipher_encrypt_one(tfm, out, prev); + + return 0; +} + +static int xcbc_init_tfm(struct crypto_tfm *tfm) +{ + struct crypto_cipher *cipher; + struct crypto_instance *inst = (void *)tfm->__crt_alg; + struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst); + struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm); + + cipher = crypto_spawn_cipher(spawn); + if (IS_ERR(cipher)) + return PTR_ERR(cipher); + + ctx->child = cipher; + + return 0; +}; + +static void xcbc_exit_tfm(struct crypto_tfm *tfm) +{ + struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm); + crypto_free_cipher(ctx->child); +} + +static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb) +{ + struct shash_instance *inst; + struct crypto_cipher_spawn *spawn; + struct crypto_alg *alg; + unsigned long alignmask; + u32 mask; + int err; + + err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask); + if (err) + return err; + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return -ENOMEM; + spawn = shash_instance_ctx(inst); + + err = crypto_grab_cipher(spawn, shash_crypto_instance(inst), + crypto_attr_alg_name(tb[1]), 0, mask); + if (err) + goto err_free_inst; + alg = crypto_spawn_cipher_alg(spawn); + + err = -EINVAL; + if (alg->cra_blocksize != XCBC_BLOCKSIZE) + goto err_free_inst; + + err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg); + if (err) + goto err_free_inst; + + alignmask = alg->cra_alignmask | 3; + inst->alg.base.cra_alignmask = alignmask; + inst->alg.base.cra_priority = alg->cra_priority; + inst->alg.base.cra_blocksize = alg->cra_blocksize; + + inst->alg.digestsize = alg->cra_blocksize; + inst->alg.descsize = ALIGN(sizeof(struct xcbc_desc_ctx), + crypto_tfm_ctx_alignment()) + + (alignmask & + ~(crypto_tfm_ctx_alignment() - 1)) + + alg->cra_blocksize * 2; + + inst->alg.base.cra_ctxsize = ALIGN(sizeof(struct xcbc_tfm_ctx), + alignmask + 1) + + alg->cra_blocksize * 2; + inst->alg.base.cra_init = xcbc_init_tfm; + inst->alg.base.cra_exit = xcbc_exit_tfm; + + inst->alg.init = crypto_xcbc_digest_init; + inst->alg.update = crypto_xcbc_digest_update; + inst->alg.final = crypto_xcbc_digest_final; + inst->alg.setkey = crypto_xcbc_digest_setkey; + + inst->free = shash_free_singlespawn_instance; + + err = shash_register_instance(tmpl, inst); + if (err) { +err_free_inst: + shash_free_singlespawn_instance(inst); + } + return err; +} + +static struct crypto_template crypto_xcbc_tmpl = { + .name = "xcbc", + .create = xcbc_create, + .module = THIS_MODULE, +}; + +static int __init crypto_xcbc_module_init(void) +{ + return crypto_register_template(&crypto_xcbc_tmpl); +} + +static void __exit crypto_xcbc_module_exit(void) +{ + crypto_unregister_template(&crypto_xcbc_tmpl); +} + +subsys_initcall(crypto_xcbc_module_init); +module_exit(crypto_xcbc_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("XCBC keyed hash algorithm"); +MODULE_ALIAS_CRYPTO("xcbc"); +MODULE_IMPORT_NS(CRYPTO_INTERNAL); |